Fear of bloating led to the removal of nutritious and delicious soy milk from the diet of China's first batch of female fighter pilots. This news from Xinhua reminded me of a question patients often ask: "Doctor, what should I do if drinking soy milk always makes my stomach feel bloated?"
In order to provide specific guidance, I looked up some materials and found relevant research: boiling soy milk for at least 10 minutes can remove 95% of the "bloating factors."
The bloating factors mentioned here are stachyose and raffinose. They are the culprits causing bloating because they are poorly reactive to heat treatment. These substances cannot be digested by our digestive enzymes and can also inhibit the activity of related digestive enzymes, making food digestion more difficult. Pilots, due to their special environment, feel this effect more acutely. Meanwhile, tofu made using traditional processes generally doesn't cause bloating because these "bloating factors" are eliminated.
The solution is to cook the soy milk thoroughly before drinking. Some might say, "To prevent poisoning and diarrhea, we already boil our soy milk." In fact, soy milk that has just reached 100°C does not completely eliminate the bloating factors. Therefore, you shouldn't drink it as soon as it boils; you need to let it simmer for about 10 minutes. If that seems too long, it's recommended to cook it for at least 5 minutes to remove about 85% of the bloating factors.
Some people worry that cooking it for too long will cause a loss of nutrients. There's no need to worry about this. For soy milk, main substances like protein and fat-soluble soy isoflavones are very stable. B vitamins, which can withstand high temperatures of up to 120°C, are also lost in very small amounts. And the most easily lost nutrient, Vitamin C, is present in minimal quantities in soy milk. Therefore, on the whole, the benefits outweigh the drawbacks.